在 2016/4/8 16:26, Linus Walleij 写道:
> On Wed, Apr 6, 2016 at 9:08 AM, qiujiang <qiujiang@xxxxxxxxxx> wrote:
>
>> This patch adds gpio-signaled acpi event support. It is used for
>> power button on hisilicon D02 board, an arm64 platform.
>>
>> The corresponding DSDT file is defined as follows:
>> Device(GPI0) {
>> Name(_HID, "HISI0181")
>> Name(_ADR, 0)
>> Name(_UID, 0)
>>
>> Name (_CRS, ResourceTemplate () {
>> Memory32Fixed (ReadWrite, 0x802e0000, 0x10000)
>> Interrupt (ResourceConsumer, Level, ActiveHigh,
>> Exclusive,,,) {344}
>> })
>>
>> Device(PRTa) {
>> Name (_DSD, Package () {
>> Package () {
>> Package () {"reg",0},
>> Package () {"snps,nr-gpios",32},
>> }
>> })
>> }
>>
>> Name (_AEI, ResourceTemplate () {
>> GpioInt(Edge, ActiveLow, ExclusiveAndWake,
>> PullUp, , " \\_SB.GPI0") {8}
>> })
>>
>> Method (_E08, 0x0, NotSerialized) {
>> Notify (\_SB.PWRB, 0x80)
>> }
>> }
>>
>> Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
>> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
>> Signed-off-by: qiujiang <qiujiang@xxxxxxxxxx>
> Admittedly I'm an ACPI novice and need help with deciding
> about ACPI, but I mostly trust Mika to know these things right.
>
> About this:
>
>> + /* Add GPIO-signaled ACPI event support */
>> + if (pp->irq)
>> + acpi_gpiochip_request_interrupts(&port->gc);
> It's weird to me that the driver already has a requested IRQ and
> everything, now it has to request it again from ACPI.
>
> When I look into the acpi_gpiochip_request_interrupts()
> I find it weird that it is void given how much can go wrong
> inside it. Should it not return an errorcode?
Just as Mika said, these are two different things:
platform_get_irq() requestedIRQ resource from interrupt subsystem and
create irq mapping, then gose ready for device, but dose not request
a handler immediately.
acpi_gpiochip_request_interrupts() parse the _AEI and _EVT object and
result awareness of what GPIO pin is used.Then, install a event handler
for each pin by request this pp->irq.
If something gose wrong when acpi_gpiochip_request_interrupts() process,
GPIO itself can still works fine.
>> + if (has_acpi_companion(dev) && pp->idx == 0)
>> + pp->irq = platform_get_irq(to_platform_device(dev), 0);
> As it was already fetched here and then later requested,
> we still have to call acpi_gpiochip_request_interrupts()
> further down the road? That is confusing to me, can you
> explain what is going on?
>
> Yours,
> Linus Walleij
>
> .
>
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